In a compressor for compressing fluid, part of lubricating oil for lubricating sliding parts of a compressing mechanism is discharged from the compressor together with compressed fluid, and circulates during a refrigerating and air conditioning cycle. As a quantity of lubricating oil discharged into the fluid during the cycle increases, system efficiency (heat efficiency) declines. Accordingly, to enhance the system efficiency, contained lubricating oil is separated as much as possible from the fluid compressed by the compressing mechanism. This separated fluid is discharged into a system cycle. Such examples are disclosed in Japanese Laid-open Patent No. H11-82352 (FIG. 1, FIG. 3, FIG. 4), and Japanese Laid-open Patent No. 2001-295767 (FIG. 1, FIG. 2). In such a conventional compressor comprising a centrifugal separation chamber, high pressure refrigerant gas containing lubricating oil compressed by a compressing mechanism is guided into a centrifugal separation chamber. This refrigerant gas revolves in this circular columnar separation chamber. By centrifugal force of this revolution, misty lubricating oil contained in the refrigerant gas contacts an inner wall of the separation chamber. As a result, the misty lubricating oil is separated from the refrigerant gas. This conventional compressor comprising the centrifugal separation chamber has a pipe called a separation pipe provided in the separation chamber. The refrigerant gas introduced into the separation chamber revolves in a cylindrical space of circular section formed between an outer circumference of the separation pipe and an inner circumference of the separation chamber. Thus, in a centrifugal lubricating oil separation system, generally, a separation pipe is regarded to be an essential constituent element. That is, to enhance separation efficiency of lubricating oil, refrigerant gas must be revolved securely in the separation chamber. For this purpose, it is considered essential to install a separation pipe in the separation chamber and revolve the refrigerant gas along the circumference. Such system of installing a separation pipe in the separation chamber results in a large-sized separation chamber. Moreover, a number of parts is increased, and manufacturing cost of the separation chamber is raised as is a number of processes increased for assembling the separation pipe, whereby it is a serious problem to reduce manufacturing costs of the compressor.
It is hence an object of the invention to solve these conventional problems and present a compressor high in terms of separation efficiency of lubricating oil, reduced in terms of a size of a compression chamber, and lowered in terms of manufacturing cost.